diff --git a/fs_mgr/libsnapshot/partition_cow_creator.cpp b/fs_mgr/libsnapshot/partition_cow_creator.cpp
index 7057223..5bc7e65 100644
--- a/fs_mgr/libsnapshot/partition_cow_creator.cpp
+++ b/fs_mgr/libsnapshot/partition_cow_creator.cpp
@@ -131,15 +131,28 @@
     return is_optimized;
 }
 
-void WriteExtent(DmSnapCowSizeCalculator* sc, const chromeos_update_engine::Extent& de,
+bool WriteExtent(DmSnapCowSizeCalculator* sc, const chromeos_update_engine::Extent& de,
                  unsigned int sectors_per_block) {
     const auto block_boundary = de.start_block() + de.num_blocks();
     for (auto b = de.start_block(); b < block_boundary; ++b) {
         for (unsigned int s = 0; s < sectors_per_block; ++s) {
-            const auto sector_id = b * sectors_per_block + s;
+            // sector_id = b * sectors_per_block + s;
+            uint64_t block_start_sector_id;
+            if (__builtin_mul_overflow(b, sectors_per_block, &block_start_sector_id)) {
+                LOG(ERROR) << "Integer overflow when calculating sector id (" << b << " * "
+                           << sectors_per_block << ")";
+                return false;
+            }
+            uint64_t sector_id;
+            if (__builtin_add_overflow(block_start_sector_id, s, &sector_id)) {
+                LOG(ERROR) << "Integer overflow when calculating sector id ("
+                           << block_start_sector_id << " + " << s << ")";
+                return false;
+            }
             sc->WriteSector(sector_id);
         }
     }
+    return true;
 }
 
 std::optional<uint64_t> PartitionCowCreator::GetCowSize() {
@@ -167,7 +180,7 @@
     // Allocate space for extra extents (if any). These extents are those that can be
     // used for error corrections or to store verity hash trees.
     for (const auto& de : extra_extents) {
-        WriteExtent(&sc, de, sectors_per_block);
+        if (!WriteExtent(&sc, de, sectors_per_block)) return std::nullopt;
     }
 
     if (update == nullptr) return sc.cow_size_bytes();
@@ -182,7 +195,7 @@
         }
 
         for (const auto& de : written_op->dst_extents()) {
-            WriteExtent(&sc, de, sectors_per_block);
+            if (!WriteExtent(&sc, de, sectors_per_block)) return std::nullopt;
         }
     }
 
diff --git a/libprocessgroup/profiles/cgroups.json b/libprocessgroup/profiles/cgroups.json
index d013ec8..3e4393d 100644
--- a/libprocessgroup/profiles/cgroups.json
+++ b/libprocessgroup/profiles/cgroups.json
@@ -1,6 +1,13 @@
 {
   "Cgroups": [
     {
+      "Controller": "blkio",
+      "Path": "/dev/blkio",
+      "Mode": "0775",
+      "UID": "system",
+      "GID": "system"
+    },
+    {
       "Controller": "cpu",
       "Path": "/dev/cpuctl",
       "Mode": "0755",
@@ -32,12 +39,6 @@
       {
         "Controller": "freezer",
         "Path": "."
-      },
-      {
-        "Controller": "io",
-        "Path": ".",
-        "NeedsActivation": true,
-        "Optional": true
       }
     ]
   }
diff --git a/libprocessgroup/profiles/task_profiles.json b/libprocessgroup/profiles/task_profiles.json
index 12f7b44..1fc66ba 100644
--- a/libprocessgroup/profiles/task_profiles.json
+++ b/libprocessgroup/profiles/task_profiles.json
@@ -76,24 +76,6 @@
       "Name": "FreezerState",
       "Controller": "freezer",
       "File": "cgroup.freeze"
-    },
-    {
-      "Name": "BfqWeight",
-      "Controller": "io",
-      "File": "blkio.bfq.weight",
-      "FileV2": "io.bfq.weight"
-    },
-    {
-      "Name": "CfqGroupIdle",
-      "Controller": "io",
-      "File": "blkio.group_idle",
-      "FileV2": "io.group_idle"
-    },
-    {
-      "Name": "CfqWeight",
-      "Controller": "io",
-      "File": "blkio.weight",
-      "FileV2": "io.weight"
     }
   ],
 
@@ -457,30 +439,11 @@
       "Name": "LowIoPriority",
       "Actions": [
         {
-          "Name": "SetAttribute",
+          "Name": "JoinCgroup",
           "Params":
           {
-            "Name": "BfqWeight",
-            "Value": "10",
-            "Optional": "true"
-          }
-        },
-        {
-          "Name": "SetAttribute",
-          "Params":
-          {
-            "Name": "CfqGroupIdle",
-            "Value": "0",
-            "Optional": "true"
-          }
-        },
-        {
-          "Name": "SetAttribute",
-          "Params":
-          {
-            "Name": "CfqWeight",
-            "Value": "200",
-            "Optional": "true"
+            "Controller": "blkio",
+            "Path": "background"
           }
         }
       ]
@@ -489,30 +452,11 @@
       "Name": "NormalIoPriority",
       "Actions": [
         {
-          "Name": "SetAttribute",
+          "Name": "JoinCgroup",
           "Params":
           {
-            "Name": "BfqWeight",
-            "Value": "100",
-            "Optional": "true"
-          }
-        },
-        {
-          "Name": "SetAttribute",
-          "Params":
-          {
-            "Name": "CfqGroupIdle",
-            "Value": "0",
-            "Optional": "true"
-          }
-        },
-        {
-          "Name": "SetAttribute",
-          "Params":
-          {
-            "Name": "CfqWeight",
-            "Value": "1000",
-            "Optional": "true"
+            "Controller": "blkio",
+            "Path": ""
           }
         }
       ]
@@ -521,30 +465,11 @@
       "Name": "HighIoPriority",
       "Actions": [
         {
-          "Name": "SetAttribute",
+          "Name": "JoinCgroup",
           "Params":
           {
-            "Name": "BfqWeight",
-            "Value": "100",
-            "Optional": "true"
-          }
-        },
-        {
-          "Name": "SetAttribute",
-          "Params":
-          {
-            "Name": "CfqGroupIdle",
-            "Value": "0",
-            "Optional": "true"
-          }
-        },
-        {
-          "Name": "SetAttribute",
-          "Params":
-          {
-            "Name": "CfqWeight",
-            "Value": "1000",
-            "Optional": "true"
+            "Controller": "blkio",
+            "Path": ""
           }
         }
       ]
@@ -553,30 +478,11 @@
       "Name": "MaxIoPriority",
       "Actions": [
         {
-          "Name": "SetAttribute",
+          "Name": "JoinCgroup",
           "Params":
           {
-            "Name": "BfqWeight",
-            "Value": "100",
-            "Optional": "true"
-          }
-        },
-        {
-          "Name": "SetAttribute",
-          "Params":
-          {
-            "Name": "CfqGroupIdle",
-            "Value": "0",
-            "Optional": "true"
-          }
-        },
-        {
-          "Name": "SetAttribute",
-          "Params":
-          {
-            "Name": "CfqWeight",
-            "Value": "1000",
-            "Optional": "true"
+            "Controller": "blkio",
+            "Path": ""
           }
         }
       ]
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 487e5da..2b04495 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -219,6 +219,26 @@
     write /dev/stune/nnapi-hal/schedtune.boost 1
     write /dev/stune/nnapi-hal/schedtune.prefer_idle 1
 
+    # Create blkio group and apply initial settings.
+    # This feature needs kernel to support it, and the
+    # device's init.rc must actually set the correct values.
+    mkdir /dev/blkio/background
+    chown system system /dev/blkio
+    chown system system /dev/blkio/background
+    chown system system /dev/blkio/tasks
+    chown system system /dev/blkio/background/tasks
+    chown system system /dev/blkio/cgroup.procs
+    chown system system /dev/blkio/background/cgroup.procs
+    chmod 0664 /dev/blkio/tasks
+    chmod 0664 /dev/blkio/background/tasks
+    chmod 0664 /dev/blkio/cgroup.procs
+    chmod 0664 /dev/blkio/background/cgroup.procs
+    write /dev/blkio/blkio.weight 1000
+    write /dev/blkio/background/blkio.weight 200
+    write /dev/blkio/background/blkio.bfq.weight 10
+    write /dev/blkio/blkio.group_idle 0
+    write /dev/blkio/background/blkio.group_idle 0
+
     restorecon_recursive /mnt
 
     mount configfs none /config nodev noexec nosuid